Improvement in adjustable tension device for sewing-machine shuttles



l. P. SCHENKL. l Adjustabie'fension Device for Sewing Machine Shuttles i i PatemedfAprn 25, 41865.

WIT/056555 We@ l ff ff@ nw. w

UNTTED STATES JOHN P. SOHENKL, OF BOSTON, MASSACHUSETTS; FREDERTKA SCHENKL AD-1 PATENT OFFICE.

MlNISTRATRIX OF THE ESTATE OF SAID JOHN P. SOHENKL, DEOEASED.` l

IMPROVEMENT IN ADJUSTABLE TENSION DEVICE FOR SEWING-.MACHINE SHUTTLES.

Specification forming part of Letters Patent No. 47,462, dated April 25, 1865.

To all whom yit may concern:

Beit known that the late JOHN l?. SCfHENKL, formerly of Boston, inthe county of Suffolk and State of Massachusetts, invented a new and Improved Adjustable Shuttle-Tension for Sewing-Machines; and I do hereby declare that the following, taken in connection-With the drawings which accom pany and form part ot' this specification, is a description of'his sa'id invention sufficient to enable those skilled in the art to practice it.

The object of this invention is to produce any desirable degree of tension upon the shuttle-thread ot a sewing-machine at the time when the needle-thread is drawing into the work. y

Said invention consists in means for el'ecting said object, substantially such as are herein Shown and described. l

In the drawings which embody said invention, Figure l shows in plan a shuttle-race with the shuttle, shuttle-driver, and-other appendages thereunto, theshell ot' the shuttle being partially broken away, so as the better to villustrate the invention, the shuttle, where broken, being shown in longitudinal section. In said figure the black lines pertaining tothe shuttle and shuttle-driver show these parts and others immediately therewith connected in the position which they have before there is any need of tension on the shuttle-thread. The red lines in said ligure show the shuttle and shuttle-driver and the parts immediately connected therewith in the position where the shuttle has passed through the loop of the needle-thread, and with tension upon the shuttlc-thread. Fig. 2 is a cross-section taken on the plane oftthe line z z, shown in Fig. l, and showing theparts in the position in which the thread is free from tension. Fig. 3 is a crosssection taken through the shuttle, and showing the parts in the position which puts a tension upon the shuttle-thread.

Within the shuttle is a spring-piece, a, fixed to the shuttle atb, and in its normal condition partly surrounding the bobbin, and located close to the shell of the shuttle, the end of the spring terminating close to the hole, through which the thread emerges from the shuttle. Said end of the spring is free to be moved on application of pressure, and it is covered bya spring a, and it will be clear that more or less resistance to the passage of the thread through said holes will be offered, according as the spring a is pressed from `its normal position away from the shuttle-shell and into the guard c. "As the spring a is thrust intoc, the pas;

sage for the thread becomes tortuous, andby further movement of a in the same direction` the thread is more or less tightly pinched be-` tween the guard c-and the end of aand this pinching may be made to stop all rendering of the thread from the bobbin during the time the pinch is maintained.

Thefmethod of operating the .springen and y of graduating its action uponthe thread, so as to suitany` size thereof, and to conform to the varying requirements of sewingmechanisms, will now be explained. l

The shuttle shown is one of a common kind,

slotted at d, as seen in Figs. 2 and 3,and also I in 'Fig."4, which is a view of the convex side, made merely to exhibit said s|ot,'which is opposite the spring-pieceya.

Secured to the shuttle-driver e is a lever, f, pivoted at g, one end of whichlever is so shaped` at h that it can freelyenter into the slot d of the shuttle, and operate therein the spring a. The other end of the lever is suita` bly shaped, as'shown, so as to be operated by impingement on the incline on piece t at each` forward motion of the shuttle. The lever f is kept in its normal position, as shown by i i the black lines inv Fig. 1, by the spring j, Vwhich is secured to the shuttle-driverfc. lt

will now be obvious that when the shuttlen driver is in its forward position (shown in red lines) the forward end of the lever will come in contact with and be pressed outward by the incline on i, and hence the other end, h, ofthe,

lever will be made to enter the slot din the shuttle, and that the extent of its entrance in said slot will dependen the position of 'the piece t', which, as itmay be seen, is adjusted within any required limit bythe screw k. To increase the tension on the thread ,the screwk is so turned as to move the piece i in adirection away from the shuttle-race, While to lessen In Witness whereof I hereunto set my hand the tension lhe screw is turned in the opposite this 11th day of March, A. D. 1865.' direction.

What is claimed is FREDERIKA SCHENKL, The arrangement and combination ofmeoh- Admm'stmtrx ofthe estate of John RSOhenkZ. mism herein describe-d, when made to operate In presence ofsubstantially in the manner and for the pur- J. B. CROSBY,

pose specified. F. GULD. 

